Redox (reduction–oxidation, pronunciation: RED-oks or REE-doks) is a type of chemical reaction in which the oxidation states of atoms are changed. Redox reactions are characterized by the actual or formal transfer of electrons between chemical species, most often with one species (the reducing agent) undergoing oxidation (losing electrons) while another species (the oxidizing agent) undergoes reduction (gains electrons). The chemical species from which the electron is removed is said to have been oxidized, while the chemical species to which the electron is added is said to have been reduced. In other words:
Oxidation is the loss of electrons or an increase in the oxidation state of an atom, an ion, or of certain atoms in a molecule.
Reduction is the gain of electrons or a decrease in the oxidation state of an atom, an ion, or of certain atoms in a molecule (a reduction in oxidation state).Many reactions in organic chemistry are redox reactions due to changes in oxidation states but without distinct electron transfer. For example, during the combustion of wood with molecular oxygen, the oxidation state of carbon atoms in the wood increases and that of oxygen atoms decreases as carbon dioxide and water are formed. The oxygen atoms undergo reduction, formally gaining electrons, while the carbon atoms undergo oxidation, losing electrons. Thus oxygen is the oxidizing agent and carbon is the reducing agent in this reaction.Although oxidation reactions are commonly associated with the formation of oxides from oxygen molecules, oxygen is not necessarily included in such reactions, as other chemical species can serve the same function.Redox reactions can occur relatively slowly, as in the formation of rust, or much more rapidly, as in the case of burning fuel. There are simple redox processes, such as the oxidation of carbon to yield carbon dioxide (CO2) or the reduction of carbon by hydrogen to yield methane (CH4), and more complex processes such as the oxidation of glucose (C6H12O6) in the human body. Analysis of bond energies and ionization energies in water allow calculation of the redox potentials.
Homework Statement
I have a test coming up and some of the practice questions were things like "Name 6 elements with a maximum oxidation state of +7" or some other number like +8, +6, etc. How do I go about doing this?
The Attempt at a Solution
There is the obvious trick of counting...
Homework Statement
Im having some problems with some oxidation and reduction mechanisms. I am not sure if I am doing them correctly.
Homework Equations
1. O=C=O + CH3-MG++I-
2. Acetone + NH4+, Na+ H3BCN
The Attempt at a Solution
1. I break one of the bonds from the oxygen...
Hi everyone,
I'm working on random materials which are coincidencely oxides and showing semiconductor behaviour... Some of these are metals and i suddenly realize MOS (which are practically everywhere). I know them, i know how they work and behave still i can't get to understand the effect of...
Few things I'm curious about regarding zirconium use in reactors. I know at high temperatures it can release hydrogen from water by forming zirconium oxide. But:
http://en.wikipedia.org/wiki/Zircaloy"
this suggests that once a surface layer is formed no more oxidation can take place...
Could someone explain the mechanism of radiolytic oxidation to me? There seems to be very little information available on the net. It is mentioned on http://www-pub.iaea.org/MTCD/publications/PDF/te_1521_web.pdf" :
Given that KMnO4 oxidises primary alcohols to aldehydes and secondary alcohols to ketones, and that in a mixture secondary alcohols will oxidise first (correct?).
What's the order of preference of primary alcohols that will most readily oxidise first.
The highest molecular weight first...
I am currently working on a project analysing inhibitors of a heme enzyme which oxidises an indole molecule. We have data on halogenated and non halogenated indoles (methyl, hydroxy, amino and nitro). I have split them into these two classes because the first group have a negative correlation...
Hi there! I have a quick question that could use some clarification. According to my textbook, an oxygen atom has an oxidation state of -1 when in the polyatomic ion peroxide, although it's -2 in most other cases. However, I've come across this problem where it asks for the oxidation state of Ti...
Just have a few questions about the cause of heart disease and oxidation of fats. I am looking for some studies that relate to the questions if possible.
1. Does saturated fat cause atherosclerosis or is it the oxidized cholesterol that usually accompanies it (as in most cooked animal...
Hi
Why does Ni only form NiO with oxidation state of +2 whereas the other transition metals form a wide range of oxides with variable oxidation states
Thanks
1. I have a question regarding an iron nail wrapped with zinc. The question asks me "Is it correct to say that corrosion did not take place in the nail wrapped with zinc? Explain."
I am not sure whether this is correct but I know that that zinc is more reactive than iron and will thus be more...
Hi
I am interested in the change in the stability of the oxidation states of manganese with pH
Mn is a stronger oxidising agent in acid than in base which would lead you to believe that the higher oxidation states of Mn are more stable in alkaline conditions.
Does anyone have a reason...
Hello- I recently etched an Altoids tin. I would like to leave the etched tin in an outdoor location as a memorial to something. The etching includes text, and I am worried about oxidation of the steel ruining the tin quickly. I would ideally like for this to last several years (as long as...
Hi
1 )
show how many electron are transferred in the following equation
a ) Cu + Ag ----- > Cu^+ + Ag
B) Zn + cl2 ----- > ZnCl2
my answer is :
A) Cu ---- > Cu ^+ + ie-
1e + Ag^+ ----- > Ag
then the electron which transfer is ( 1 )
B ) Zn + cl2 ---- zncl2
Zn...
If I have SO42-, I can figure out that the oxidation state of each O ion is 2- and the sulfur ion must then be 6+. What does this number mean? What does it tell you about the electrons in that molecule?
Pretty exciting development to convert water to hydrogen and oxygen appears in http://www.sciencemag.org/cgi/content/abstract/science.1185372" ).
The catalyst is based on Co4O4 stabilized with bulky polytungstate ligands. The best part is that the complex spontaneously organizes into the...
What is the point of adding the sodium dichromate dehydrate in water solution dropwise to benzhydrol in glacial acetic acid? Why can't we just add it all in at once? Also, what is the purpse of the glacial acetic acid?
I can't understand the term oxidation number.According to my textbook, it is the charge assigned to an atom. But for what purpose we are doing this?Is it for identifying the oxident and reductant in a reaction?If yes, on what basis the rules (for assigning oxidation states) are implemented...
This isn't a homework question, but seemed sufficiently low-level that it belonged in this part of the forum.
When one speaks of "common" oxidation states, what is meant by "common?" Is this simply to say the states most commonly occurring in nature? This would be opposed to most commonly...
I have a question regarding the possible oxidation states of metals. I understand how to find the oxidation state of a metal in a compound, that's pretty straightforward. What I'm interested in is finding possible oxidation states given only the name of the metal. For example, Cu has possible...
I posted this on thedishforum:
On the German soapmaking forum, there are several posts noting that there seems to be a correlation between ash and oxidation of oils. Can you speak to the presence of ash and soap going rancid?
And got this reply:
Yes, I could see this being an accurate...
On the German soapmaking forum, there are several posts noting that the presence of ash and the oxidation of oils(rancidity) often go together.
When the ash appears in small amounts, I have not noticed any oxidation. When the ash develops over much of the surface of the soap bars, the soap...
Homework Statement
http://carlodm.com/pictures/problem.png
The Attempt at a Solution
I'm stuck. Usually I balance the equation by multiplying the Fe(OH)2 and Fe2O3 by 3. However, I can no longer do this because Fe2O3 has two iron's per one molecule.
Do I multiply one by 6 and...
Determine the oxidation numbers of the underlined elements in the following formulas:?
If you could explain each one, it would be greatly appreciated. Thanks!
a) KClO3
b) NH4+
c) Cr2O72-
d) MnO42-
In the oxidation of organic chemicals, are there any conditions that must involve water or must not be in the presence of water or the oxidation process will stop despite the presence of the oxidizing agent? I remember my teacher saying something about this, but I don't remember which one it is...
Homework Statement
Calculate the oxidation no. of Nitrogen in:
NH4NO3
Homework Equations
O=-2
H=+1
The Attempt at a Solution
N H4 N O3
+4 -6 = -2 to make it equal zero
then 2N=+2 hence N=+1
Or NH4=+1 then N=-3
NO3=-1 then N=+5
I have two related questions on PbTiO3 perovskite structure and chemical environment.
The Pb K-egde Xanes data reveals that Pb is in a mixed valence state of Pb4+ and Pb2+. However in literature Pb is claimed to be in Pb2+ state. The Pb 6s2 electrons hybridize with the O 2p electrons to form...
Ok so the question goes as such: Write the half equation for the oxidation reaction and then the full net ionic equation for KMnO4 solution mixed with dilute HCL. My main problem is what is getting oxidised?
Hello!
I just registered on these forums and this is my first post here, so hopefully I did everything right.
I recently got into metalworking in my spare time, and I am trying to create a metal alloy that will remain liquid at room temperature (a fusible, eutectic alloy). From what I've...
What happens when alcoholic beverages are left exposed to air?
i read that they are oxidised to ethanoic acid. Strictly only ethanoic acid? Why not say, propanoic acid? Or a mixture of acids possible to be present? Is it because only ethanol is present in alcoholic drinks? If so, only ethanol then?
How come atoms have only a few oxidation numbers they can assume? For example, Cl can have the oxidation numbers -1, 1, 3, 5, 7. What prevents it from having an oxidation number of say, 2 or 4?
My friend needs to clean his head light lenses and they are plastic , does anyone know a chemical that will dissolve plastic or clean the lens to cut the oxidation , i could buff the lens but i would rather use a chemical, I was thinking along the lines of lacquer thinner.
balance the following oxidation reduction reactions. which is the oxidizing agent? reducing agent?
()my answer as balance
a) P4 + Cl2 =(4)PCl5 reducing agent P, o agent Cl
b) Sn2+ + Cu2+ = Sn4+ + Cu+ reducing agent...
Determine the oxidation number for each atoms in the following compounds or ions:
a) H3 0+
ox # -2
b)P4 O10
ox #-3
c)S8
ox #5
d)H2 CO
ox #4
e)NH4 CLO4
ox #2
I need help to know if i am doing it right.
determine the oxidation number for Mn in each of the following:
a) KMnO4
is the ox # -3
b) LiMnO2
is the ox # +1
c) MnO2
is the ox # +2
d)K2 MnCl
is the ox # +1
e)Mn2 O7
is the ox # -10
I need help ASAP PLEASE!
The question is True/False.
The answer is false, and I don't know why. All those oxidation #s seemed to make sense to me, and I couldn't think of any others.
Any thoughts as to why that's not true?
My original question:
Why do oxidation reactions from primary alcohols to aldehydyes/carboxylic acids, or secondary alcohols to ketones require an acid (positive hydrogen ion)? I can see that the reason we have an oxidizing agent is to take away two hydrogen ions from the alcohol, but
why do...
Hi guys, my teacher once told me that if there's a benzene with a side chain which has a carbon group (e.g. aniline or benzaldehyde or 3-phenylpropane) it will be oxidise into benzoic acid, no matter what it is.
So my question now is, does oxidising phenylethanal gives me benzoic acid? or say...
Just a brief question on oxidation numbers. My textbook says "the oxidation number of the more electronegative atom in a moledule or a complex ion is the same as the charge it would have if it were an ion." However, when considering compounds like hydrazine N2H4, Nitrogen is clearly the more...
Homework Statement
3Ag2 S + 2Al --> 6Ag + Al2 S3
consider the equation for silver tarnishing.
a) state the oxidation number for each element in the reaction.
b)identify the the oxidized reactant and the reduced reactant.
The Attempt at a Solution
Ag2=2 S= -2 Al=0 --->...
Hello,
I'm writing a paper on the effect oxidation has on creep in metals. I'm a bit lost as I've been able to find is papers on this topic for specific metals. Could anyone suggest a good paper or good book that could help light the way that talks on diffusion creep or better still the...
Homework Statement
This is from a lab question, but i think i did it right, i would just like some confirmation. I had to make an electochmical cell for a lab, (actually mutiple ones) but it asks me to find the anode, cathode, and which chemical underwent oxidation and reduction. If you have...
At what point in either beta-oxidation or citric acid cycle is ATP used?
I see where ATP is produced in citric acid cycle (originally as GTP) as when succinyl CoA is converted to Succinate, but I can't find any part where ATP is required. Apparently according to my lecture notes, it is...
Homework Statement
I wasn't sure about some of these problems, am I doing them correctly?
1) What volume of each of the following bases will react completely with 25.00 mL of 0.200 M of HCl?
a) 0.100 M NaOH
.02500 L x .200 mol HCl/1 L = .00500 mol HCl
.100 M NaOH = .00500 mol...
Homework Statement
Is this oxidation or reduction: (NO3)- ---> NO (this is a half reaction I took from the full equation)
Homework Equations
Not necessary
The Attempt at a Solution
At first, I got the oxidation states of each of the atoms
For (NO3)- N has an oxidation...
Hello:
I am having some trouble relating to the following question to the concept of oxidation numbers as required by my practice problem, and would appreciate any help.
Thank you!
---
1. Explain why it is dangerous to grind a mixture of Al with KClO4 in a mortar and pestle.
---...
Homework Statement
Why does the stability of highest oxiation state decreases from group 13 to group 17?
Ans: My book says, that with the increase in atomic number, difference in energies between ns and np orbitals increases. Is it right? If so then can u please explain what relation...